Muffles



4R. JIMacKENzlE ET AL Re. 21,324

` Jan. 16, 1940.

KUFFLER Original Filed July 8, 1936 2 Sheets-Sheet 1 INVENTOR 5ATTORNEYS Jan 16, 1940. R. J. MacKENzlE ET A1. Re- 21,324

,MUFFLER Original Filedl July 8, 1936 2 Sheets-Sheet 2 KWKINVENTORS24u41, C. www

ATTORNEYS OLII/gun,

Reissued Jan. 116, 1940 UNITED STATES PATENT orties.

Starkweather, Youngstown, Ohio, assignors to Y Buffalo Pressed SteelCompany,uia1o, N. Y.

Original No. 2,115,113, dated April 26, 1938, Serial No. 89,606, July S,1936. Application for reissue June 22, 1938, Serial No. 215,240

15 Claims.

This invention relates to improvements in mufflers such, for example, asare used for silencing the exhaust from internal combustion engines,land more particularly to muiliers of this kind f I@ having chambersformed between pairs of shells.

One of the objects of this invention is to provide a muffler of improvedand simpliiied construction for forming a chamber between two shells.

Another object of this invention is to provide a muffler having a shelldivided lengthwise of its vaxis into a plurality of sections or parts,which may be secured together to form the completed shell.

Another object is to provide a shell of this type which is formed to besecured to and supported by another shell. y

Another object of -this invention is to provide a longitudinally dividedshell which taires the place of a cylindrical shell and two or morebaffles for mounting the shell on another shell.

A further object of' this invention is to so forni a split or sectionalshell that the chamber formed vby such shell with another shell isconnected by a passage with another chamber to forni a bottle neck typeof resonator chamber.

Another object of this invention is to provide a split shell with ajoint or connection between the two parts of the shell, which is groovedor 30 channeled to form a passage for sound Waves.

Other objects of this invention will be apparent from the followingdescription and claims.

In the accompanying drawings: Fig. l is a longitudinal, central,sectional view 35 of a muffler provided with sectional shells ern-,hodying this invention.'

Figs. 2, 3 fl and.5 are transverse sections thereof', respectively onlines -2'-2, '3-3, IiL--ll and 5--5, of Fig. l.

a shell. of another modied construction.

Fig. l2 shows another modied form of sectional niuflier shell. l

,n Fig. 13 is a fragmentary, longitudinal, central,

Fig. 6 is a side View of a sectional muili-er shell ll. is a tace viewof one section or part of (o1. isi-4s) sectional View of a muilierhaving the shell shovm in Fig. l2 installed therein. v

Fig. i4 is a transverse, sectional View thereof, on line |4-l4, Fig. 13.

Figfl illustrates, by way of example, a muffler 5 in which three formsof sectional shells embody ing this invention areemployed, and thismuiiler includes an outer shell A, end heads B and C, and a perforateinner conduit D. The end head B may oe provided with the usual integraltubu- 10 lar extension l5 telescopically connected with an exhaust pipei6. The head B is also provided with a short, tubular part Il' securedwithin the tubular extension l5 of the head B and telescoping into oneend of the inner shell or con duit D. The other head C is provided witha tubular extension or part I8 with which the usual tail pipe (notshown) is telescopically connected, and this tubular part I8 alsoreceives the discharge end of the inner shell or conduit D. The conduitD, in the construction shown, is provided with groups of perforations orapertures 20 having louvres 2l formed of the metal oi the innery shellor conduit bent outwardly at the apertures 2t in such a manner thatgases lpassingl out of 25 the inner shell or conduit through theapertures 2i! will be discharged substantially in a tangential directionwith relation to the conduit D. It will be understood., however, thatapertures of any other shape or size and with or without louvres may beemployed through which gases may flow into and out of the inner shell orconduit. 22 represents a baiiie extending from the inner shell orconduit D tothe outer shell A, which divides the space immediatelywithin the outer shell into two chambers. The inner shell or Conduit ispreferably provided with an annular outwardly1 bent or formed rib orprojection 23A Whichextends outwardly beyond the outer edges of thelouvres 2i and to which the inner flange 2li of the baille 40 E2 may hesecured. By means of this outwardly extending projection 23, the innerdiameter of the Vflange M of the baflie can be made large enough so thatthe conduit may be passed through the hole in the baiiie withoutinterference by the louvres and the ange M will then rit tightly aroundthe annular raised rib or projection .23.

In muflers of this type, it is customary to provide an intermediateshell ory shells arranged about the conduit D within the outer shell A,and these intermediate shells are connected with the inner or outershells by means of baffi-es which are generally welded to the shellswhich they conneet. We have found that it is more desirable undercertain conditions to employ `one or more u intermediate shells, each ofwhich may be made in sections or parts having longitudinal edges orIianges which may be connected or secured together to form the completeshell. These sections also have integral shoulders or parts con nectedwith another shell or conduit.

At the left-hand end of Fig. 1, between the head B and the baie 22 isarranged a split shell according to our invention which, as clearlyshown in Figs. 2, 3 and 4, consists of two sections or half shells 25and 26, both of these half shells being provided with laterallyextending iianges 21 which may be readily secured together by Welding orother means. The vsplit intermediate shell shown in this portion of themuffler is shaped to form two chambers 28 and 29, and at the outer endof the chamber 28, the shellis provided with an inwardly extendingshouldered or offset portion terminating in a substantially cylindricalange 3D which is arranged to engage, for example, an imperforate portionof the inner shell or conduit. At the other end of the chamber 28, themetal ofthe intermediate shell is also depressed inwardly and formsanother annular shoulder or offset 3| also engaging and secured to aportion of the inner shell or conduit. At the left end of the chamber 29in Fig. 1., portions of the intermediate shell are depressed toward theinner shell or conduit, as shown at 33, and may be welded or otherwisesecured to the conduit D. Other portions 34 of this end of the splitintermediate shell are not deformed or bent into contact with the innerconduit D, and these portions, consequently, form, with imperforateportions of the conduit D, channels or bottle necks 35. These bottlenecks or channels connect the chamber 29 between the split intermediateshell and the conduit D with a chamber or space 36 arranged between theintermediate shell and the outer shell A. The length as well as thecross sectional area of these channels or bottle necks 35 can, ofcourse, be Very easily varied, so as to silence, by destructiveinterference, certain sound waves passing Fig. 1, an Vinner' shell isshown which is formed of two halves o-r sections 4U and 4| constructedto form two chambers 42 and 43, each closed at both ends similar to thechamber 28, which has been described. Chambers of this kind may be usedto cooperate with the inner shell or conduit and with the perforationstherein to silence high frequency sound waves. The chambers 42 and 43are closed at their endsby inwardly curved shoulder portions of the twosections 40 and 4|, which inwardly curved portions also engage portionsof the inner shell or conduit D for supporting the sections 4U and 4| ofthe intermediate shell on the conduit D, as well as closing the ends ofthe chambers 42 and 43.

At` the right-hand end of the muiiler shown in Fig. l, still anotherform of intermediate shell is illustrated. This shell comprises twosections and 46, see Fig. 5, secured together by Yilanges as alreadydescribed. In this case, the sections of 'the intermediate shell form ahigh frequency chamber 41 of larger diameter than. the chambers 2B, 42and 43 and, which may, consequently, be used in silencing another bandof frequencies other than that Isilenced in the chambers 28, 42 and 43.This chamber 4`| is closed at opposite ends by integral shoulderedportions. The secftions 45 and 45 also form another chamber 48 about theinner shell or conduit D, and in this case, the chamber 48 alsocommunicates with the space between the intermediate shells and theouter shell A by means of a short channel or bottle neck 49. Half ofthis channel is formed in the flange of one of the sections of theintermediate shell, and the other half is formed by the other section,the two halves of the channel being arranged to form a completesubstantially cylindrical channel 49 as shown in Fig. 5. It will "bereadily seen that the cross sectional area and shape of this channel canbe readily varied, as may be required, to produce the desired silencingaction in connection with the outer resonator chamber 50 which is formedbetween the outer shell A and the intermediate shells, and between theballie 22 and the head C.

In Figs. 6 and 7, a split or sectional muffler shell is shown which isVery similar to the shells 4|) and 4| shown in Fig. 1, except that inFigs. 6 and 7, the outer edge of one of the anges of the two sections isturned over the edge of the other ange, as shown at 52, to form a seamconnecting the anges of the two sections 53 and 54 of the shell. In theconstructionof the various shells shown in Fig. 1, the flanges of thesections of the shell are described as being welded together, and thismay be done as indicated in Figs. 2-5 inclusive, at 55.

In Figs. 8 to l0, still another modied form of a sectional muilier shellis shown. In this construction, the shell has two sections SD and 5|,the flanges of which are secured together about the inner shell orconduit, three shouldered portions 62, 63 and 64 being provided whichextend into engagement with the inner shell or conduit D. The portionsof the two sections between the two shoulders 63 and E4 form about theperforate portion of the conduit D an annular closed resonator chamber.between the shoulders 62 and 63 form a chamber which communicates withan outer chamber 65, Fig. 9, by means of passages or bottle necks B6formed by means of'oppositely` disposed grooves The portions of thesections l in each of the flanges of the two muiiier sections l 6D and6|. The construction shown in this figure is particularly suitable foruse in connection with the silencing ofcertain sound waves orbands vdesired, the inner ends of these passages may terminate in the space orchamber B1 between the sectional shell and the conduit at differentdistances from the inner end `of the chamber 51.

If a still longer passage or bottle neck is required to produce thedesired silencing eiects, the construction shown in Fig. 11 may be used,in

. which one-half of a split shell is shown which diiiers from the shellshown in Figs. 8 to 10, in that a chamber 10 is formed at the left-handportion of the shell and in which the passages or bottle necks 1|communicate with a chamber 12 located at the right-hand end oi' thesplit shell. In this construction, the length of the passages 1| may bevaried by terminating the inner ends of the passages at differentportions of the chamber T2. Thisconstruction results in a passage orbottle neck of about twice the length of the one shown in Figs. 8 to 10.

Figs. 12 to 14 show a sectional shell formed in two sections 15 and 1B,the anges of which are formed to provide inclined passages `or bottleInf 'lll

necks 'H which terminate at their outer ends in the vside edges of theanges of the two sections of the shell.

It Will be obvious from the foregoing description that the muillersembodying this invention may be varied greatly, not only with referenceto the construction and shape of the sectional shells, but also thesectional shells may be used in connection with the usual cylindricalshells and baiiles heretofore commonly employed. It will also beunderstood that while the sectional shells are herein illustrated asused in connection with an inner shell or conduit, they may equally Wellbe used in connection with. another shell arranged about the innershell. The sectional shells may, if desired, be formed of more than twosections.

The construction described has the advantage that the sectional shellsmay be readily applied to an inner shellhaving outwardly projectinglouvres such. as illustrated in Fig. 3 without necessitating anoutwardly extending annular ridge, such as the ridge 25.? shown in Fig.1, since the sections ol? the shell are preferably first placed intooperative relation to each other about the inner shell and are thensecured to each other and to the inner shell, so that it is notnecessary to slide the completed sectional shell lengthwise of the innershell into its operative position, although, if desired, in connectionwith. inner shells having no outwardly extending projections or louvres,the several sections of the shell may be rst secured together and thenslid lengthwise of the inner shell into its correct position.

By forming shells in sections as herein described, and by formingshoulders on the sections, which may extend into engagement with anothershell, the use of two or more baffles connecting two telescoping shellsis eliminated, and furthermore, the provision of passages or bottlenecks in the connecting flanges of the sections results in aninexpensive construction for producing such bottle necks. The sectionsof the shell are, of course, most readily formed from flat sheets ofmetal by pressing the same into the desired shapes by means of dies.

We claim as our invention:

1. A muffler including an. inner shell having a perforate portion, anouter shell, and an intermediate shell arranged about said perforateportion of said inner shell, said intermediate shell including aplurality of sections which are substantially coextensive longitudinallyand which have their longitudinal edge portions connected to each otherto form a complete shell, said sections having integral end portionsextending into engagement with said inner shell and having a portionintermediate of its ends which extends into engagement with said innershell, whereby said intermediate shell is supported from said innershell and forms therewith chambers separated from each other, saidintermediate shell also forming at least a portion of the inner wall ofanother sound deadening chamber.

2. A muler including an inner shell having a plurality of groups oiperiorations arranged lengthwise of said shell and separated'by anannular imperforate zone. an outer shell, and an intermediate shellarranged about said groups of perforatons, said intermediate shellinclu-ding a plurality of sections having flanged longitudinal edgeportions connected to each other to form a complete shell and havingintegral end portions extending into engagement with said inner shellbeyond said groups of perforations an-d having an integral portionintermediate of its ends which extends into engagement with saidimperforate zone between said groups, whereby said intermediate shell issupported from said inner shell and wherebyinner chambers separated fromeach other are formed about said inner shell, said intermediate shellalso forming at least a part of the inner wall of another sounddeadening chamber.

3. A muliler including an inner shell having ai perforate portion, anouter shell, and an intermediate shell arranged about said perforateportion of said inner shell and including a plurality of sections havingflanges at their longitudinal edges, the flanges of adjacent sectionsbeing set cured together to form a shell enclosing said perforateportion, annular portions of said sections extending into engagementwith said inner shell for supporting said intermediate shell on saidinner shell, said intermediate shell being provided with an openingformingy a passage connecting the space between said inner andintermediate shells with a space formed between said intermediate andouter shells.

4. A muier including an inner shell having a.-4

periorate portion, an outer shell, and an intermediate shell arrangedabout said perforatev portion of said inner shell and forming therewitha high frequency resonator chamber, said intermediate shell including aplurality of sections connected to each other at longitudinal edgeportions thereof and having' end portions extending into engagement withsaid inner shell for supporting said intermediate shell on said innershell and for forming end walls of said resonator chamber, saidintermediate shell also forming with said outer shell a low frequencyresonator chamber.

5. A muiiler including an inner shell having a plurality of groups ofperforations arranged lengthwise of said shell and separated by anannular imperiorate zone, an outer shell, and an intermediate shellarranged about said groups of perforations, said intermediate shellincluding a plurality of sections having longitudinal edge portionsconnected to each other to form a'complete shell and having end p0rtionsextending into engagement with said inner shell beyond said .groups ofperforations and having a portion intermediate of its ends which extendsinto engagement with said imperforate acne between said groups, wherebysaid intermediate shell is supported from said inner shell and wherebyhigh :frequency resonator chambers separated from each other are formedabout said inner shell, said intermediate shell also forming with saidouter shell a resonator chamber for 10W frequency sound waves.

6. A mufler including an inner shell having a perforate portion, anouter shell, and an intermediate shell arranged about said perforateportion of said inner shell and including a plurality of sections havingflanges at their longitudinal edges, the flanges of adjacent sectionsbeing secured together to form a shell enclosing said periorate portion,the ends of said sections extending into engagement with said innershell for supporting said intermediate shell on said inner1 shell, aportion or a iiange of one section being spaced from the ilange of anadjacent section to orm a passage connecting the chamber between innerand intermediate shells with an outer chamber formed between saidintermediate and outer shells and forming with said outer chamber abottle neck resonator chamber.

7. A muiller including an inner shell having a plurality of groups ofperforations arranged lengthwise of said shell and separated by annularimperforate sones, an outer shell, and an interj mediate shell arranged4about said groups of perforations, said intermediate shell including aplurality of sections having longitudinal edge portions provided withoutwardly extending flanges, the flanges of adjacent sections b eingsecured toi'iqgether to form a shell enclosing adjacent groups ofperforations, said sections havingend portions extending inwardly intocontact with. said inner shell, and a portion intermediate of said endswhich extends into contact with an imperforate tu zone of inner shell,whereby said intermediate shell forms with said inner shell a pluralityof chambers, a portion of the flanges of said sections adjacent to `oneof said chambers `being spaced apart to form a passage from said chammber to a chamber formed between said intermediate and outer shells.

8. A muiiier including an inner perforate shell, an outer shell, and anintermediate shell arranged between said inner and outer shells andincluding il a plurality of sections having longitudinal edge portionsconnected to each other to form a complete shell and having end portionsand an intermediate portion extending into engagement with said innershell for supporting ysaid intermediate i shell on said inner shell andforl forming with said inner shell a plurality of chambers, a portion ofthe flanges of said sections adjacent to one of said chambers beingspaced apart toform albottle neck passage from said chamber to a chamberformed between said intermediate and outer shells.

9. A muffler including an inner shell having a perforate portion, anouter shell, and an intermediate shell arranged about said perforateportion of said inner shell and including a plurality of sections havingflanges at their longitudinal edges, the iianges of adjacent sectionsbeing secured together to form a shell enclosing said perforate portion,the ends of said sections extending into engagement with said innershell for supporting said intermediate shell on said inner shell, and toform a chamber between said inner and intermediate shells, an end of oneof said sections having a longitudinal portion thereof spaced from animperforate portion of said inner shell to form therewith a bottle neckpassage connecting said chamber with a chamber' formed between saidintermediate `and outer shells.

10. A muilier including an inner shell having a perforate portion, anouter shell, and an intermediate shell arranged about said perforateportion of said inner shell and including a plurality of sections havingflanges at their longitudinal edges, the fianges of adjacent sectionsbeing se- Cured together to form a shell enclosing said perforateportion, the ends of said sections extending into engagement with saidinner shell for supporting said intermediate shell on said inner shell,and for forming a chamber between said inner and intermediate shells, atleast one of said flanges having a groove in the face thereof adjacentto an adjoining ilange of another section, said groove terminating atone `end thereof in said chamber and at the other end thereof in thespace between said outer and intermediate shells to form with anadjacent ange a passage connecting said chamber with said spiace.

11. A muler including an inner shell having a perforate portion, anouter shell, and an intermediate shell arranged about said perforateportion of said inner shell and including a'plurality of sections havingflanges at their longitudinal edges, the flanges of adjacent sectionsbeing secured together to form a shell enclosing said perforate portion,the ends of said sections extending into engagement with said innershell for supporting said intermediate shell on said inner Shell and forforming a chamber between said inner and intermediate shells, a pair ofadjacent flanges being provided with grooves facing each other andextending fromsaid chamber to the outer edges of said iianges, saidgrooves together forming a. bottle neck passage connecting said chamberwith. a chamber formed between said intermediate and outer shells.

12. A muffler including an inner shell having a perforate portion, anouter shell, and an intermediate shell arranged about said perforateportion of said inner shell and forming therewith an inner chamber, saidintermediate shell including a plurality of longitudinal sections eachextending from end to end of said intermediate shell and having theirlongitudinal edge portions secured together and having portionsextending into engagement with said inner shell for supporting saidintermediate shell on said inner shell and forming end. walls of saidinner chamber, said intermediate shell also dividing the space betweensaid inner shell and said outer shell into separate chambers.

i3. A muli-ler including an inner shell having a perforate portion, anouter shell, an intermediate shell arranged about said perforate portionof said inner shell and forming therewith an inner chamber, saidintermediate shell including a plurality of longitudinal sections eachextending from end to end oi said intermediate shell and having their flongitudinal edge portions secured together and having portionsextending into engagement with said inner shell for supporting saidintermediate shell on said inner shell and for forming end walls of saidinner chamber, said intermediate shell also forming with the cuter shellan outer chamber, said intermediate shell being provided with an openingestablishing communication between said inner and outer chambers.

14. A mullier including three shells arranged one within another andspaced radially from each other, end walls connecting the inner andouter of said shells, an intermediate wall arranged between said endwalls and also connecting the inner shell with the outer shell, theinner of said shells having a perforate portion, the intermediate ofsaid shells being arranged about said perfcrate portieri and positionedbetween one of said end heads and said intermediate wall, saidintermediate shell including a plurality of longitudinal sections .eachextending from end to end of said intermediate shell and having theirlongitudinal edge portions provided with flanges which are securedtogether to form a continuous intermediate shell encircling a portion ofsaid inner shell, each of said sections having portions extending intoengagement with said inner shell for supporting said intermediate' shellfrom said inner shell and forming end walls for a chamber formed betweensaid inner and intermediate shells, said intermediate shell also formingat least a part of the inner wall of a chamber formed between saidintermediate and outer shells.

l5. A muliler including an inner shell having perforate and imperforatezones of its wall spaced apart in a direction lengthwise thereof, anouter shell, and an intermediate shell disposed within 'and spacedlargely from said outer shellen being formed intermediate of the ends ofthe intermediate shell, some of vsaid constricted zones being inapproximate Contact with said inner shell throughout approximately theentire periphery of 10 the latter to form separated chambers between theinner and intermediate shells on opposite sides of a constriction, saidintermediate shell being split lengthwise fromend to end tc enableapplication over the inner shell in a direction laterally thereto, andhaving abutting ilanges along and substantially continuous with thesplit on opposite sides thereof, that extend outwardly of v saidintermediate shell, whereby said intermediate shell may be easily ttedover an inner shell having an irregular outer surface.

ROY J. MACKENZE..

LUCIEN L. HAAS.

GAIL C. S'IARKWEATHER.

